This invention relates to improved roofing shingles or tiles, of the type that are laid over an underlayment in a series of rows on a roof, and in particular, relates to dimensional molded roofing tiles that do not accumulate water beneath them that can lead to premature roof material failure.
In conventional roofing systems, an underlayment comprising asphalt roofing felt is laid over a plywood underroofing. Wooden strips or battens are then laid in tranverse rows over the underlayment, and the roofing tiles are nailed, through nail holes provided in the tile, directly to the batten. Battens are generally one inch by two inch boards that are laid down in both horizontal and vertical courses of approximately twelve to sixteen inch intervals. Alternatively, the tiles are nailed directly through the asphalt underlayment to the plywood underroofing without using battens. The disadvantage posed by such construction methods is that the upper ends of dimensioned roofing tiles installed in such fashion tend to act as small water dams during rain. Furthermore, in cold climates, melting snow can likewise dam up on a dimensioned tile, and even worse, is subject to refreezing, which can cause even more material damage. Dimensioned roofing tiles, as opposed to less expensive asphalt-type roofing shingles, are thicker, being made of materials such as wood, concrete, terra cotta, ceramic, stamped metal and the like. Dimensioned tiles are chosen by architects and homeowners for their unique and distinctive exterior appearance and their longer lifetimes, compared to asphalt shingles. As water is dammed up on the relatively thick upper edges of such dimensioned tiles, it thus pools onto the underlayment, tending to lead to premature material failure. In those situations where nails are driven into the underlayment itself instead of into a batten, such pooled water is even more likely to be able to seep into the underlayment material. These retained-moisture situations tend to lead to premature failure of the roof tile material and of the underlayment.
Prior art solutions to this problem generally have included the provision of so-called weep holes at the top of a roofing tile that make allowance for water that would otherwise have dammed up at the top of the tile to more freely flow down under the courses of the tiles. See the disclosure of U.S. Pat. No. 4,432,183, issued Feb. 21, 1984 to Pike, et. al., and U.S. Design Pat. No. 347,287, issued May 24, 1994 to Mayer. One requirement of the prior art is that in order to minimize seepage into underlayment, even with the inclusion of weep holes, that tiles not be nailed into the underlayment, but rather into battens, and that adhesives be applied to at least part of the bottom surface of the tiles. See Pike U.S. Pat. No. 4,432,183. The requirement of battens adds to the cost of installing a roof, as does the necessity of applying an adhesive to a tile. Additionally, any system that uses a batten needs some provision for drainage through the batten itself, which can act as a water dam for the same reasons given above as for dimensioned roof tiles. Thus, it is an object of the present invention to provide for a roofing tile that does not require the application of adhesives or the installation of battens, while being able to minimize water damming at the tops of the tiles during rain and minimize water saturation and damage to underlayment and tile material itself.
Wooden shakes and shingle have been a popular roofing material in upscale homes, yet pose a serious fire hazard, especially in drier climates. They also present an additional fire hazard to the rest of the community, since, under certain windy conditions, hot embers from a blazing wooden roof can get blown onto neighboring roofs and likewise start them on fire. An additional object of the present invention is to provide for an alternative to the use of wooden shakes or shingles so as to mimimize the fire hazard potential of a roof, while affording the look of a wooden shake or shingle roof.
Prior art roofing tiles have typically been relatively heavy, with thick-walled construction that uses materials such as concrete not being unusual. Therefore, another object of the present invention is to provide for a roofing material that is relatively light in weight, yet is able to withstand a relatively heavy load.
Prior art roofing tiles have typically required the use of a slightly different embodiment of the tile for the first course of tiles that is laid down by the installer and that is closest to the eaves. Therefore, it is yet another object of the present invention to provide for a roofing system whose installation does not require an alternative embodiment for the installation of the initial course of tiles that is nearest the eaves.
The present invention achieves these objects by providing for a roofing tile that features molded construction of a suitable thermoplastic or thermosetting resin into the weight-saving shape of a box that achieves greater rigidity and weight bearing capacity through the inclusion of a central weight bearing rib; an elongated drainage slot in the upper portion that is a high efficiency water conduit; and that, by virtue of its design, does not require a different embodiment of the initial course that is laid down nearest the eaves. The advantages posed by the roofing tile of the present invention are easier installation by elimination of laying down battens or applying adhesives; reduced fire hazard; improved water drainage that acts to prolong material life; and lighter weight that reduces shipping costs and reduces the load-bearing requirements of the building structure.